XB98 - Check Continuity Between A/C Pressure Switch and PCM

- Key "OFF".

- A/C cyclic pressure switch disconnected.

- Disconnect Powertrain Control Module (PCM). Inspect for damaged or pushed out pins, corrosion, loose wires, etc. Service as necessary.

- Install breakout box, leave PCM disconnected.

- Measure continuity between test Pin 10 at the breakout box and the circuit to the PCM / Variable Control Relay Module (VCRM) at the A/C Cyclic Pressure Switch vehicle harness connector.

- Is resistance less than 5.0 ohms?

Yes -- Replace PCM. Remove breakout box. Reconnect all components. Re-evaluate symptom.

No -- Service open circuit between the A/C cyclic pressure switch and the PCM. Remove breakout box. Reconnect all components. Rerun quick test. Quick Test Appendix (Detailed Testing Instructions)